Apparatus for pulverizing pavement and the like



June 1956 J. P. SILVESTRI 2,752,141

APPARATUS FOR PULVERIZING PAVEMENT AND THE LIKE Filed July 21. 1953 52 Fig. 2

Fig. 4

Joseph P. .Si/vesfri IN VEN TOR.

F ig.3 y g Attorneys 2,752,141 APPARATUS FOR PULVERIZING PAVEMENT AND THE LIKE Joseph P. Silvestri, San Mateo, Calif. Application July 21, 1953, Serial No. 369,432 1 Claim. (Cl. 262-15) This invention relates generally to pulverizing apparatus and pertains more particularly to an improved apparatus for pulverizing or breaking pavement and the like.

A primary object of this invention is to provide an improved impact hammer for pulverizing or breaking pavement and other similar structures which requires not only a minimum of efiort but also a minimum of time.

Another object of this invention is to provide an apparatus for pulverizing or breaking pavement and the like which comprises an impact instrument mounted upon a moving vehicle so that the instrument effects progressive striking operations on the material to be pulverized in such a manner as to effect progressive fracture, breaking or pulverization, of the surface worked upon which requires a minimum of energy from the impact tool.

Another object of this invention is to provide an improved impact tool head for use in particular with the apparatus hereinafter described.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a side elevational view of the invention in use;

Figure 2 is a horizontal section taken substantially along the plane of section line 2-2 of Figure 1, showing details of the breaking operation on enlarged scale;

Figure 3 is a perspective view of the impact head; and

Figure 4 is a front end view of the assembly shown in Figure 3.

Referring now more parn'cularly to the drawings, reference numeral 10 indicates generally a truck or any other suitable vehicle which is provided with the usual ground engaging steering wheel 12 and drive wheels (not shown) for moving the truck a normal manner over the ground. The truck may be provided with an air compressor (not shown) and an air reservoir tank 14 which is provided with a pair of outlet lines 16 which extend forwardly therefrom on the outside of the truck to connect at opposite ends to the cylinder member 18 which forms a part of the air hammer assembly indicated generally by the reference character 20. The door 22 of the truck on the drivers side is provided with a pair of brackets 24 which secure the control valve 26 thereto, its control knob 28 being positioned conveniently for operation by the driver of the truck.

A supporting frame assembly indicated generally by the reference character 28 is secured to the front bumper and associated frame work of the vehicle and this assembly includes a plurality of uprights 30, a lower support member 32, an upper support member 34 and suitable cross brace members 36. Multiple upright guide posts 38 are provided on the front of the assembly and these members are preferably of circular cross section so that the apertured ears 40 on the cylinder member 18 may be slidably and guidably engaged therewith. The support head 42 of the impact tool is provided with an eye 44 which receives one end of the cable member 46 suitably wound upon the winch or drum assembly 48. This drum nited States Patent 2,752,141 Patented June 26, 1956 or winch may be either manually operated exteriorly of the truck or it may be provided with a power drive means derived from the truck engine, as is well known and understood. The purpose of this winch assembly is to raise and lower the impact hammer for proper positioning above the surface 50 of the material being pulverized or broken.

The impact tool assembly includes a piston rod 52 having the tool head 54 mounted thereon. As seen most clearly in Figures 3 and 4, the tool head takes the form of a truncated three-sided pyramid whose upper side 56 is disposed in rightangular relation to its rear face, the rear face defining a relatively large trimgle. The upper edges 58 and the lower edge 60 of the tool are disposed in mutually convergent relation terminating at the smaller triangular front face 62 of the tool so that the lower edge 60 presents an upwardly inclined cutting surface.

With the hammer assembly positioned in a proper vertical position, the control valve 26 is opened to reciprocate the piston rod 52 and hence the tool 54 while the truck 10 is moving over the ground surface which will effect progressive impact along the line 64 in Figure 2, this line being engaged by the lower edge 60 of the head 54.

As the tool is reciprocated up and down and the truck is moved forwardly over the surface being pulverized, it will be readily apparent that a wedging or splitting action occurs along the line 64 due both to the forward movement of the truck 10 as well as the taper of the tool head, this taper being provided in both a longitudinal and a transverse direction for most effectively breaking or splitting the pavement which will require a relatively small input of energy into the impact tool than would normally be required should the tool be held in a stationary position.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claim.

What is claimed as new is as follows:

A device for pulverizing and breaking pavements comprising an attachment for mounting on the forward end of a self-propelled vehicle having an operators cab, said attachment comprising a vertically disposed frame, a cylinder and piston mechanism vertically adjustably mounted on said frame, a piston rod extending downwardly from the cylinder, a tool on the lower end of the piston rod for impact with a pavement, and pneumatic means for reciprocating said piston rod and tool for breaking a pavement, remote control means for said pneumatic means positioned adjacent the vehicle cab for manipulation by the vehicle operator, said tool having inclined surfaces that are joined along an inclined longitudinal line and that terminate in a vertical rear surface, said surfaces extending to their lowermost point rearwardly along the path of movement of the tool thereby progressively breaking a pavement by reciprocation of the tool during longitudinal movement of the vehicle.

References Cited in the file of this patent UNITED STATES PATENTS 2,254,477 Ferguson Sept. 2, 1941 2,656,169 Stich Oct. 20, 1953 2,659,583 Dorkins Nov. 17, 1953 FOREIGN PATENTS 13,511 Great Britain of 1893 

